Tim,
my 94 & 97 short door cars were fine but I know the early ones were weaker.
That's good, John. I thought the better heaters came with the long-door cars as all the ones I've been in have excellent heaters.
My 1986 car is utter rubbish in this regard. A poxy little axial fan with two speeds: slow, or slow and noisy. I can fart more warm air than it can push out. That's why I'm so keen to learn more about Phil's upgrade.